Hello Theraputic

Sewing Tutorial: Therapeutic heat (or cooling) pack with washable cover, by Shelley & Lara on www.howdoesshe.com (20 May 2010). I've seen patterns for these filled with rice, wheat, and flax. This one uses dried corn kernels (NOT popcorn). I wonder how they compare to the other fillers? I like that these have removable, washable covers.